The present invention relates to changeover parts for a conveyor such as an air conveyor which changes the height at which objects are conveyed and in particular to changeover parts which are rotatable to accommodate a plurality of heights of conveyed objects.
Conveyor systems, such as pressurized air conveyor systems, belt conveyors and the like, are sometimes called upon for conveyance of objects which have a plurality of sizes. For example, a conveyor system might be used in one period of time for conveyance of a larger sized object, and during another period of time, conveyance of a smaller sized object. A changeover part is a part which is used in connection with conveying objects from one portion of a conveyor system to another portion of a conveyor system. Certain types of changeover parts produce a positioning of the conveyed objects which is different depending on the size of the object conveyed.
FIGS. 1A and 1B illustrate this situation. FIG. 1A depicts, in cross-section, a first conveyor system 12 and a second conveyor system 14. In this case, the first conveyor system 12 is a pressurized air conveyor system for conveying ring-necked bottles 16a. The neck of the ring-necked bottles 16a include a ring 18 supported by guide rails 20a, 20b. Movement of the bottles 16a is achieved by directing pressurized air from a conduit or plenum 22 through apertures of an apertured wall 24 of the plenum 22 to direct streams of pressurized air against the bottles 16a. Secondary guide rails 26a, 26b can also be provided. A description of a pressurized air conveyor can be found in U.S. Pat. No. 4,284,370, issued Aug. 31, 1981, to Danler, et al. The second conveyor system 14 depicted in FIG. 1A is a belt conveyor system. To transfer objects 16a from the first conveyor system 12 to the second conveyor system 14, it is necessary to have a changeover part, which, as the objects 16a are conveyed, will change the level of conveyance so as to align the bottom of the object 16a with the belt 14. Thus, the changeover part will have guide rails which are ramped downward an amount equal to the distance 28a between the bottom of the object 16a and the belt of the second conveyor 14.
FIG. 1B depicts the situation when a smaller object 16b is conveyed by the first conveyor system 12. Because of the smaller size of the object 16b, a changeover part with a different configuration is needed. In the situation in FIG. 1B, a changeover part must be more highly sloped in order to move the object 16b vertically a distance 28b so as to align the bottom of the object 16b with the belt of the second conveyor system 14.
Previous conveyor systems typically approached this problem by providing changeover parts which were difficult to insert into the system. Typically, a set of changeover guide rails which might be used in the configuration shown on FIG. 1A would be removed such as by removing bolts or other holding devices, a second set of guide rails would be positioned in place of the removed first set of guide rails and the second set of guide rails would then be attached such as by bolting or the like. This procedure of removing and installing changeover parts was labor-intensive and time-consuming, and required the shutdown of the conveyor line for a relatively long period of time. This system also imposed the burden of maintaining and storing an inventory of changeover parts.
Another changeover system used a set of guide rails which could be positioned in a variety of heights or slopes using a type of parallelogram-linkage. Although this system for moving the guide rails permits adjustment to any intermediate position within a range, it is complicated and expensive. The movable guide rail system includes a large number of moving parts which require a large space for installation and are subject to wear and thus decrease reliability of the device. Further this system failed to provide positive drive over the entire length of conveyance, instead providing pressurized air drive only over portions of the path of conveyance. Provision of positive drive for the entire length of the path is particularly important in feed regions where, unlike a typical discharge region, there is little or no accumulation of objects. Thus the objects are typically fed one at a time and receive no conveyance assist from succeeding accumulated objects.
Accordingly, it would be useful to provide a changeover part which can accommodate a plurality of sizes of conveyed objects which is fast and easy to reconfigure, which reduces the number of moving parts used in previous devices and which reduces wear on components, particularly the guide rail system.